Table 2.

The role of β2 integrins in tumor development.

Subunit	Cell Type	Species	Tumor Model	Observations	Reference
CD18	S100A8+ myeloid cells	m	Lewis lung carcinoma (LLC) and MC38 colon adenocarcinoma	Tumors growing in CD18hypo, but not in CD11b-deficient mice were more sensitive to irradiation in comparison to WT mice	[309]
	B cell	h	CLL	CD18 variant (E630K) enhances CLL susceptibility	[321,331]
CD11a	NK, TC	h	-	Establishment of an intercellular synapse with cancer cell and targeted release of granules depend on LFA-1	[331,332,333]
	B cell	h	CLL	Impaired motility and accumulation in the blood due to defective Rap-1 GTPase signaling/diminished CD18 expression	[320,324]
CD11aCD11b	PMN	m	Melanoma	ICAM-1 expressing melanoma cells bind PMN via LFA-1/MAC-1, and thus are carried across the vasculature forming metastasis	[319]
CD11b	PMN	m	B16F10 Melanoma, RM1 prostate cancer	CD11b−/− PMN fail to infiltrate tumor tissue and secrete VEGF needed for the neovascularization at lower extent	[310]
		m	spontaneous intestinal adenoma	CD11b−/− myeloid cell infiltrate tumor mass at low extent, associated with diminished tumor growth and impaired Wnt/β-catenin activity in the tumor	[305]
		m	Squamous cell carcinoma xenografts	Systemic application of CD11b blocking antibody increased anti-tumor response after radiation	[309]
		h	Gastric cancer	Extent of CD11b+ cell infiltration correlated with tumor size, venous invasion, lymph node metastasis, general metastasis stage and FoxP3+ cell infiltration	[307]
		h	Epithelial ovarian cancer (EOC)	de novo expression of MAC-1 on EOC cell lines	[334]
		m	Melanoma	MAC-1 is essential for antibody-mediated antitumor responses	[313]
CD11c	APC	h	Gastric cancer	CD11c+ cell tumor infiltration correlated with tumor size.	[307]
CD11d	Macro-phage	m		Upregulation of CD11d/CD18 surface expression by myeloid cells is associated with their accumulation at the inflammation site and chronification of inflammation	[67]